Heretofore, certain types of emulsions have been especially difficult to resolve by electrostatic means. These emulsions include: (1) high water content liquid membrane emulsions, (2) crude petroleum tanker and refinery sludges, and (3) oil-continuous emulsions contaminated with electrically conductive catalyst fines.
Another problem with electrostatic coalescer apparatuses is that their current-carrying electrodes often develop pin-hole leaks in the electrode insulation. These leaks result in arcing and general breakdown of the electrode's capability to resolve the emulsions. In addition, many electrodes are comprised of glass or other frangible materials, such that they are easily and often broken.
Emulsions with suspended fines and solids have shown particular difficulty in being resolved, even when alternating current having frequencies in excess of 60 Hz are employed. Such a teaching is given in the United States Patent to L. R. McCoy, U.S. Pat. No. 3,770,605; issued: Nov. 6, 1973.
Also, extreme resolution difficulties have been observed with electrically conductive liquids, even despite the utilization of frequencies as high as 1,000 Hz. For purposes of definition, electrically conductive liquid emulsions are generally in the range of from 0.1 to 1.times.10.sup.-10 or 1.times.10.sup.-12 ohm.sup.-1 cm.sup.-1.
A teaching of this aforementioned problem is given in the United States Patent to L. R. McCoy and L. L. Prem, U.S. Pat. No. 3,839,176; issued: Oct. 1,1974.
The present invention seeks to resolve the problems set forth above, and in addition, desires to provide other advantages in coalescer methods and apparatus.
The subject invention has successfully treated electrically conductive and solids-containing emulsions at frequencies about 60 Hz. The invention has developed a new, solids pump-off tube in combination with a rugged electrode which makes possible improved emulsion-breaking techniques, including dramatic increases in the throughput of the coalescer system.